Abstract
Keywords
Vision impairment is one of the most common disabling conditions experienced by older adults. It is primarily the result of four major age-related eye diseases: macular degeneration, glaucoma, cataract, and diabetic retinopathy. For older adults, vision loss tends to have a gradual onset with a chronic course of decline, yet it seldom results in total blindness (Faye, 2000). Between 13% and 20% of community-dwelling older adults report functional vision problems, even when wearing corrective lenses (Crews & Campbell, 2001; Horowitz, Brennan, & Reinhardt, 2005; Ryskulova et al., 2008). The prevalence of vision problems is even higher among nursing home residents: Between one-third and one-half of all long-term care residents have some level of vision impairment (Friedman, Munoz, West, Rubin, & Fried, 2002). Although a paucity of research has focused on the prevalence and consequences of vision impairment in older adults receiving subacute rehabilitation in long-term care settings, evidence exists that vision loss is prevalent in this subgroup; about 20% have visual acuities worse than 20/60 (Lieberman, Friger, & Lieberman, 2004). Patients in subacute long-term care tend to be older adults admitted for medical care and rehabilitation (e.g., occupational or physical therapy) to recover from an injury (e.g., hip fracture) or acute illness (e.g., cancer) after an acute-care hospital stay.
Progressive vision impairment can increasingly and significantly affect a person’s functional ability (Burmedi, Becker, Heyl, Wahl, & Himmelsbach, 2002) and interaction with the physical and social environments (Wahl & Oswald, 2000). Given the relationship between vision loss and disability in later life, prior research, not surprisingly, has consistently documented high rates of depression in older adults with vision impairment. Approximately one-third of older adults with vision impairment report clinically significant depressive symptoms (Horowitz, Reinhardt, Boerner, & Travis, 2003; Reinhardt, 2001; Rovner & Casten, 2002). Moreover, vision impairment increases fear of falling (Kempen, van Haastregt, McKee, Delbaere, & Rixt Zijlstra, 2009), the risk of falling, the risk of falls with injuries (Patino et al., 2010), and hip fractures (Cummings et al., 1995) and is a strong predictor of future falls (Friedman et al., 2002). An association between vision impairment and higher mortality risk has also been documented (Lee, Gómez-Marín, Lam, & Zheng, 2002; Pedula et al., 2006).
Occupational therapy is effective in improving functional abilities in community-dwelling older adults with health conditions such as rheumatoid arthritis, stroke, and dementia (see, e.g., Steultjens, Dekker, Bouter, Leemrijse, & van den Ende, 2005; Steultjens et al., 2004; Voigt-Radloff, Schochat, & Heiss, 2004). Evidence also demonstrates that vision loss hinders the full utilization and successful outcomes of physical rehabilitation. Lieberman et al. (2004) found that length of stay in the rehabilitation unit and efficacy of rehabilitation after a hip fracture were significantly lower in older adult patients with vision impairments than in those without vision impairments. In a follow-up study, having a vision impairment was one of eight significant predictors of worse postrehabilitation physical functioning in patients with hip fractures (Lieberman, Friger, & Lieberman, 2006).
In addition to the well-established negative effects of vision impairment on physical and mental health outcomes, vision impairment may affect utilization intensity and outcomes of physical rehabilitation. However, little research has addressed this issue, particularly the impact of vision impairment on intensity of occupational therapy utilization and outcomes (i.e., improvements in functioning) in patients receiving subacute care in a long-term care setting. Research on these topics is essential for the development of evidence-based occupational therapy interventions that can address the negative effects of vision impairment alongside the medical condition that prompted admission to the subacute care unit. Addressing vision impairment in this context is crucial to ensuring that patients reach rehabilitation goals more efficiently and, after discharge, are equipped with the necessary skills to function independently and safely.
The purpose of this study was to explore the effects of objective and subjective indicators of vision impairment severity on intensity of occupational therapy utilization and outcomes of occupational therapy—specifically, functional dependency at discharge from a subacute care unit—when controlling for other factors, including sociodemographic characteristics, social supports, and other physical and mental health variables. We aimed to answer whether vision impairment has an adverse impact on occupational therapy minutes received and functional dependency at discharge after controlling for health-related and other variables.
Method
Research Design
In this cohort study, we used structured in-person interviews, including subjective and objective assessments of vision impairment severity, conducted at admission to a subacute rehabilitation unit, as well as admission and discharge data from medical chart review after discharge from the unit. All study procedures and protocols were approved by the institutional review board of Jewish Home Lifecare, New York, NY, and all participants provided written consent after being read the details of study procedures, potential risks and benefits, and use of data.
Recruitment and Participants
Participants were recruited from the pool of older adults newly admitted to a subacute rehabilitation unit at a long-term care facility in New York City. Criteria for inclusion were age 55 or older, English speaking, and the absence of cognitive or hearing deficits (determined by the patient’s physician) that could interfere with the in-person interview. Of the 216 eligible participants who were contacted, 100 participated in the interview and 116 declined participation, a response rate of 46%. Of the patients who declined to participate, the principal reasons given were “not interested” (77%), “unhappy with the services” (9%), or “not feeling well” (4%). We found no statistically significant differences regarding age and gender between the group who declined participation and the group who participated in the study.
Outcome Measures
Sociodemographic Characteristics.
Single items assessed participants’ age, gender, race or ethnicity, education, and living arrangements before admission to the subacute unit.
Social Resources.
We assessed perceived availability of family and friend affective support with a single item using a 4-point scale (1 = not at all, 4 = most of the time). Another single item was used to assess perceived adequacy of family and friend affective support using a 4-point scale (1 = a lot more help needed, 4 = got all the help I needed; Cantor & Brennan, 2000). Higher scores are indicative of greater perceived availability and adequacy of social support.
Cognitive Status.
We used the 13-item Modified Telephone Interview for Cognitive Status (TICS–M; de Jager, Budge, & Clarke, 2003) to assess cognitive function. The TICS–M includes four domains: (1) orientation; (2) registration, recent memory, and delayed recall (memory); (3) attention and calculation; and (4) semantic memory, comprehension, and repetition (language). Scores can range from 0 to 39; higher scores indicating better cognitive functioning. The TICS–M was designed for telephone administration but can also be administered face to face. Unlike the Mini-Mental State Examination (MMSE; Folstein, Folstein, & McHugh, 1975), the TICS–M does not have items that are vision dependent. Beeri, Werner, Davidson, Schmidler, and Silverman (2003) found the TICS–M to have high internal consistency (Cronbach’s α = .98) and a strong convergent validity with the MMSE (r = .82, p < .0005). The TICS–M’s internal consistency on the basis of the present data was adequate (Cronbach’s α = .77).
Depression.
We used the Patient Health Questionnaire–9 (PHQ–9; Kroenke, Spitzer, & Williams, 2001) to assess depression. This nine-item self-report questionnaire is designed to evaluate the presence of depressive symptoms during the prior 2 wk. Each item can be scored on a scale ranging from 0 (not at all) to 3 (nearly every day). As a severity measure, scores can range from 0 (absence of depressive symptoms) to 27 (severe depressive symptoms). The PHQ–9 has been found to have sound psychometric properties, with an internal reliability of .89 and internal consistency of .84 (Kroenke et al., 2001). Internal consistency for the present sample was .70 using Cronbach’s α.
Experience of Pain.
We assessed pain experienced within the past 24 hr (yes–no) with one item of the Modified Residents’ Verbal Brief Pain Inventory (Auret et al., 2008).
Eye Diseases.
Participants were asked to report whether their eye doctor had ever told them that they had any of the following major age-related eye diseases: macular degeneration, glaucoma, cataract, and diabetic retinopathy. Because a person can have more than one eye disease, multiple answers were allowed.
Subjective Vision Loss Severity.
We measured subjective vision impairment impact with the 15-item self-report Functional Vision Screening Questionnaire (Horowitz, Teresi, & Cassels, 1991), which assesses the extent to which vision loss causes difficulty in specific functional areas (e.g., difficulty reading labels on medicine bottles; difficulty recognizing faces across an average-size room). Each item is scored 0 (no difficulty) or 1 (difficult) for a potential total score ranging from 0 to 15. Higher scores are indicative of a higher number of functional areas that have been compromised by vision loss and, thus, greater subjective vision impairment severity. We did not perform internal consistency analyses because this instrument is an index.
Objective Vision Loss Severity.
To measure visual acuity, we conducted binocular distance acuity testing in a darkened room using the Good-Lite Portable Eye Chart (Model A; Good-Lite Co., Elgin, IL), which is small and lightweight with its own source of standardized illumination. Higher visual acuity scores indicate poorer visual acuity. Reliability analyses have shown adequate test–retest reliability (r = .895) for the chart (Arditi & Cagenello, 1993).
To measure contrast sensitivity, we assessed binocular contrast sensitivity using the Mars Contrast Sensitivity chart (Mars Perceptrix, Chappaqua, NY), which is a version of the Pelli–Robson Chart (Pelli, Robson, & Wilkins, 1988) modified to fit the Good-Lite (Arditi, 2005). Contrast sensitivity is a measure of the ability to perceive differences between an object and its background. It is often compromised by age-related eye diseases, such as macular degeneration, and contributes significantly to falls and injuries in older adults (Turano, Rubin, Herdman, Chee, & Fried, 1994). Higher contrast sensitivity scores indicate more optimal contrast sensitivity. Reliability analyses found the Mars test to have better repeatability (and hence accuracy) than the Pelli–Robson test. The coefficient of repeatability was .182 for the Pelli–Robson chart and .121 for the Mars chart (Thayaparan, Crossland, & Rubin, 2007).
Medical Record Data.
The number of medications taken at admission was extracted from patients’ medical records and used as an indicator of comorbidity. For an indicator of intensity of occupational therapy utilization, we calculated the number of occupational therapy minutes used from patients’ medical records at discharge. Functional dependency scores based on occupational therapists’ assessments and evaluations at admission and discharge were also taken from medical records. The occupational therapy–based Functional Dependency Scale, which was developed for internal use at Jewish Home Life Care, New York, assesses functional limitations in feeding, upper- and lower-body dressing, grooming, toileting, and toilet transfer on a 6-point scale with one item for each variable (0 = independent, 5 = dependent). Higher scores reflect more functional dependency. Occupational therapists use this scale in clinical evaluations for the purpose of developing a plan of care on admission to the subacute unit. On its basis, therapy goals are delineated, and intensity of therapy is determined according to the patient’s admission status and ability to achieve those goals. No psychometric properties have been established. However, internal consistency analyses using data from the present sample showed that Cronbach’s α was .89 for the admission dependency scale and .92 for the discharge dependency scale, indicating high internal consistency.
Data Collection
Data were collected upon the patient’s admission to the subacute unit by trained interviewers through in-person interviews lasting approximately 60 min. Additional data on admission and discharge were collected by means of medical chart review after discharge.
Statistical Analysis
Descriptive analyses were run on all study variables. We computed a correlation matrix to examine the interrelationships between the independent variables and the outcome variables of occupational therapy use in minutes and functional dependency at discharge. Finally, we used multiple regression analysis for multivariate tests of the effects of independent variables on each of the two outcome variables. To predict occupational therapy utilization, we entered sociodemographic variables (age, gender, race, education, living arrangement), social support indicators (perceived emotional support availability and adequacy), admission health indicators (cognitive assessment, depression, number of medications, experience of pain, functional dependency), and vision loss severity indicators (self-reported functional problems due to vision, vision acuity, and contrast sensitivity) into the regression analysis. To predict functional dependency at discharge, we entered the same groups of variables into the regression analysis as well as occupational therapy minutes used.
Results
Descriptive Analyses
Table 1 presents sociodemographic, health, and service-related characteristics of participants at admission and descriptive analyses for all study variables including means, standard deviations, and actual ranges (whenever appropriate). Of the participants, 32% were classified as having a vision impairment on the basis of an acuity score in the better eye of 20/40 or worse, a standard used in many epidemiological studies to define impairment (e.g., the Beaver Dam Eye Study; Klein, Klein, Jensen, Moss, & Cruickshanks, 1994). On the basis of the more stringent criteria of 20/60 or worse in the better eye (World Health Organization, 1992), 13% of the participants were classified as having low vision.
Sociodemographic, Health, and Service-Related Characteristics (N = 100)
N = 97.
Note. PHQ–9 = Patient Health Questionnaire–9; SD = standard deviation; TICS–M = Modified Telephone Interview for Cognitive Status.
Average functional dependency scores decreased from 13.42 at admission to 7.39 at discharge, indicating important gains in independent function after receiving occupational therapy services. To further determine rehabilitation effectiveness on a descriptive level, we calculated an average of the percentages of patients who achieved independent functioning and those who made progress toward independent functioning at discharge across the six functional limitations of the occupational therapy evaluation, comparing admission scores with discharge scores. The average success rate for reaching independent functioning at discharge was 60%, and the average success rate for additional patients to make progress toward independent functioning was 27%, indicating that occupational therapy was successful in promoting independence in 87% of patients.
Correlational Analyses
Table 2 depicts bivariate relationships between predictor variables and the two outcome variables. On a bivariate level, more occupational therapy minutes used was significantly associated with higher perceived emotional support availability and higher functional dependency at admission to the subacute unit. Higher functional dependency at discharge was associated with being racial/ethnic minority, lower scores on the cognitive assessment tool, more medications taken at admission, higher functional dependency at admission, and higher visual acuity scores (higher visual acuity scores are indicative of poorer visual acuity).
Bivariate Correlations of Study Variables With Outcomes
Note. n/a = not applicable; PHQ?9 = Patient Health Questionnaire–9; TICS–M = Modified Telephone Interview for Cognitive Status.
p < .05. **p < .01.
Multivariate Analyses
The regression of occupational therapy minutes used on predictor variables accounted for 35% of the variance (see Table 3). Perceived emotional support availability and adequacy, depression, functional dependency at admission, and contrast sensitivity each contributed a unique portion of the variance in this outcome variable. Contrast sensitivity was a significant predictor of occupational therapy minutes used when controlling for sociodemographic, health, and social support variables. Participants who reported more emotional support availability and adequacy and fewer depressive symptoms, who were more functionally dependent at admission, and who had better contrast sensitivity were more likely to have used more occupational therapy minutes.
Summary of Multiple Regression Analyses Predicting Service Utilization (Occupational Therapy Minutes Used) and Rehabilitation Outcome (Functional Dependency at Discharge)
Note. n/a = not applicable; SE = standard error.
p < .05. **p < .01. ***p < .001.
The regression of functional dependency at discharge on the basis of occupational therapy assessments on predictor variables accounted for 63% of the variance (Table 3). Number of medications taken at admission, functional dependency at admission, occupational therapy minutes used, and visual acuity each contributed a unique portion of variance in this outcome variable. Visual acuity was a significant predictor of functional dependency at discharge when controlling for sociodemographic, health, and social support variables. Individuals who were taking more medications at admission, were more functionally dependent at admission, and had decreased visual acuity (indicated by higher visual acuity scores) were more likely to be more functionally dependent at discharge.
Discussion
We explored the effects of vision impairment on intensity of occupational therapy use and outcomes of occupational therapy—specifically, functional dependency at discharge from the subacute care unit—when controlling for factors such as sociodemographic, social support, and other physical and mental health variables.
We found that objective vision impairment severity measures had a negative impact on intensity of use of occupational therapy services and on functional dependence at discharge. Specifically, participants with compromised contrast sensitivity were less likely to use the full extent of occupational therapy services, and participants with decreased visual acuity were less likely to become less functionally dependent on discharge from the subacute unit. These findings are consistent with prior research that has demonstrated that vision impairment serves as an inhibiting factor to rehabilitation use and outcomes (Lieberman et al., 2004, 2006). Our research adds to the literature by identifying the role vision impairment plays in the use and outcomes of occupational therapy services. Objective indicators of vision impairment appear in particular to hinder full use of occupational therapy and the achievement of improved functional independence. Hence, these findings underscore the importance of addressing vision loss at the same time as occupational therapy services are delivered for the medical condition that prompted the admission to the subacute care unit.
Both study outcomes were also affected by functional dependency at admission, a finding that is not surprising because functional dependency at admission represents an evaluation of a patient’s functional limitations and is the determining factor in how much occupational therapy is prescribed on an individual level. Functional dependency at admission also is the baseline measure for the follow-up functional dependency evaluation conducted at discharge.
This study also demonstrated that both perceived availability and adequacy of emotional support were predictors of intensity of occupational therapy use but not of functional independence at discharge, which may mean that family members and friends are instrumental in encouraging a patient to take advantage of occupational therapy but do not necessarily influence therapy outcomes. Similarly, depressive symptoms played a role in use intensity of occupational therapy but had no influence on outcomes of the therapy received. In fact, results indicated that other health-related variables such as fewer medications taken at admission and, not surprisingly, more time in occupational therapy are related to more optimal occupational therapy outcomes as indicated by improved functional independence at discharge when compared with admission. Against expectations, having experienced pain was related to neither occupational therapy use nor functional independence at discharge.
Finally, on a descriptive level, we found further support for the effectiveness of occupational therapy services by examining success rates related to restoring complete independence and trends for improved independence in performance skills that inhibit occupational participation. On average, across all six performance skills, 60% of patients achieved independence and about another 30% made progress toward independent functioning.
Implications for Occupational Therapy Practice
This study adds to the knowledge base on the influence of vision impairment on the use and outcome of occupational therapy services. Our results have implications for the development of evidence-based interventions that can address the negative effects of vision impairment in conjunction with the medical reason that prompted admission to the subacute care unit to ensure that patients can reach rehabilitation goals more efficiently and to reduce limitations in performance skills that may inhibit occupational participation. One such intervention approach could entail the implementation of a low vision self-management program through which patients could receive a low vision exam and training in assistive device use and activities of daily living (ADLs) that may be specifically compromised by vision (e.g., meal and financial management). Occupational therapists may effectively facilitate the use of such interventions not only because they represent one of the main providers of service in rehabilitation hospitals and subacute care units but also because they frequently provide low vision rehabilitation services in these settings as well as in the community (Owsley, McGwin, Lee, Wasserman, & Searcey, 2009). This approach could help facilitate patients’ engagement in meaningful and purposeful life activities, including ADLs, social participation, work, and leisure activities. Moreover, this approach would also allow occupational therapists to function as advocates for subacute care patients with vision loss and as educators to inform other rehabilitation team members about vision loss issues.
Finally, the finding that the number of depressive symptoms functioned as a predictor of less intensive use of occupational therapy services suggests that mental health specialists on subacute rehabilitation units also need to be involved in the implementation of any interventions designed to address vision loss in conjunction with standard occupational therapy.
To summarize, the results of our study have the following implications for occupational therapy practice:
Vision loss adversely affects the effective use of occupational therapy.
Vision loss should be addressed as part of subacute care to optimize rehabilitation outcomes.
Mental health issues, particularly depression, also may mediate use of occupational therapy.
Occupational therapists can facilitate interventions specific to low vision in collaboration with vision care and mental health specialists in subacute care.
Limitations
Study limitations included a relatively small sample size and a sample that was well educated and recruited from the pool of cognitively intact patients at one subacute facility in one large city. Another limitation was the use of a clinical evaluation tool as opposed to a research instrument with well-established psychometric properties for the purpose of assessing functional independence. Moreover, these occupational therapy assessment tools did not include a participant’s occupational profile regarding vision loss; rather, the focus of the evaluation and therapy was the condition that prompted admission to the subacute unit, and vision loss was addressed as it related to the provision of services for this condition. Finally, we did not use a patient satisfaction survey to assess patients’ views and opinions of the services received.
Future Research
Future work should focus on suburban and rural settings, include participants with varied educational levels and cognitive abilities, and explore the influence of patient satisfaction with services on occupational therapy utilization and outcomes. Moreover, future research efforts should first test the feasibility of implementing evidence-based interventions facilitated by occupational therapists and designed to address the negative effects of vision impairment in conjunction with the medical reason that prompted admission to the subacute care unit. These research efforts should also test these interventions’ effectiveness in optimizing patient outcomes, especially their effectiveness in promoting independence and occupational participation, reducing falls, and reducing the risk of rehospitalization.
Footnotes
Acknowledgments
We thank Kathrin Boerner for comments on prior versions of this article and Jasmine Rodriguez, Aimee Cegelka, and Serena Byrd for their help with data collection and data processing.